Carpeting manufactured from staple fibers or continuous filaments may often become charged with static electricity upon being subjected to friction, especially when used at low humidity. This tendency is especially noticeable for hydrophobic fibers, such as polyamide, polyester, acrylic and polyolefin fibers. This can result in a variety of problems, such as the sound of the electrostatic discharge, clinging of garments, and electric shock, and interference with electronic apparatus, such as computers.
Prior techniques have addressed this problem by incorporating a small quantity of conductive fibers in the textile fiber material or the backing component of the fabric to act as a static dissipation element. For example, U.S. Pat. No. 4,756,941 to McCullough et al. discloses an electroconductive tow or yarn made from continuous filaments or staple fiber yarns. The yarns are prepared from stabilized petroleum pitch, coal tar pitch or a synthetic fiber forming material which on at least partial carbonization is electroconductive. The yarns are formed into coil-like fibers or filaments by winding the tow or yarn into a cloth, and heat treating the thus formed tow or yarn to a carbonizing temperature to set a coilure therein as well as electroconductive properties thereto. McCullough et al. describe the use of a blend of nylon and conductive fibers to form a web which is then needle punched onto a polypropylene spunbonded backing to give a conductive carpet.
U.S. Pat. No. 3,955,022 to Sands describes a primary carpet backing comprising a woven or bonded nonwoven sheet of continuous filaments having needled thereto a layer of a blend of staple fibers. The staple fibers include a synthetic organic polymeric fiber containing conductive carbon.
Despite these and other techniques for forming an antistatic fabric, it would be desirable to provide an antistatic fabric having a substantially uniform distribution of the conductive fibers throughout, so as to provide good static dissipation properties. This would in turn reduce the need for using antistatic chemicals or other additives in the fabric for static reduction. Further, it would be desirable to provide a fabric having conductive fibers which are firmly secured and held into place.